No.. I believe it'll be the same as the ESTA which we have to get to travel by air to the USA..
Its just a 3yr (EU may be less) computerised visa that allows frequent travel till it runs out then apply for another online.. a simple online form which you fill in, pay the $14 fee then wait 24hrs for approval/rejection of your visa, this gives you a reference number which you print off or keep saved in a file on your phone
.. still get the 90 days.
Nothing to do with sailing around.